Concrete may be loaded at an early age for a variety of reasons. This loading can have negative and sometimes destructive effects on the hardened properties of concrete. Therefore, in the present ...study, the mechanical properties of fiber-reinforced geopolymer concrete after loading at an early age have been investigated. In the present study, the effect of preload on compressive strength at the ages of 28 and 90 days for geopolymer concrete containing fibers has been investigated. For this purpose, the samples were loaded at ages of 1, 3, and 7 days, equivalent to 30 and 70% of their compressive strength at the same age. The samples were then treated again in a humid environment and subjected to compressive loading at 28 and 90 days of age. The effect of preload on flexural strength as well as energy absorption of geopolymer concrete containing fibers was also investigated. Steel fibers with volumetric percentages of 0.25, 0.5, 0.75, and 1 and polypropylene fibers with volumetric percentages of 0.25, 0.5, and 0.75 were used in fabricating laboratory samples. The results demonstrate the positive effect of fibers on reducing the destructive effects of preload on compressive and flexural strength. The effect of fibers on reducing the destructive effects of 1-day preload is higher at higher loading percentage (70% pre-loading), such that the samples containing fibers with preload of 30% at the age of one day experienced a 28.8% increase in 28-day compressive strength, while this increase was 33.2% for the samples with preload of 70%. Samples containing 0.75% polypropylene fibers at 28 and 90 days of age compared to those containing 0.25 and 0.5% polypropylene showed less energy absorption on average due to preloading. In general, the design containing 0.25 polypropylene fiber and 1% steel fiber had the best result of flexural strength among preloaded samples.
Nowadays pozzolans are used vastly in civil projects. Pozzolan is a natural or artificial material containing active silica that increase the strength and improves some properties of concrete. In ...this survey for investigating some important properties of concrete, silica fume and fly ash was used in replacement of cement in different weights. Concrete compositions were made with water-cement ratio of 0.45 and cured under the same conditions. The main focus of this survey is to investigate the individual and combined effect of using Pozzolan on mechanical properties, permeability and shrinkage of concrete. The mechanical properties of concrete in compressive and bending strength at the age of 7, 28 and 90 days, were evaluated. Permeability was investigated with the water absorption test. The drying shrinkage of concrete was monitored for 90 days. Scanning Electron Microscopy (SEM) images was used in concrete cement based matrix morphology. The results showed that the addition of pozzolan increases the mechanical strength and reduce permeability and increase the drying shrinkage in some mixtures.
Amoebic liver abscess in a patient from Gambia Callejón Fernández, M; Kohan, R; López Lirola, A M ...
Revista española de quimioterapia,
04/2023, Letnik:
36, Številka:
2
Journal Article
A 35-kbp region of genomic DNA encoding the human muscle phosphofructokinase (HPFK-M) gene including all of the coding exons (1-22) plus 2.2-kbp of 5'-flanking sequence has been cloned. The exon ...boundaries are the same as has been observed for the rabbit muscle phosphofructokinase (RPFK-M), the human liver phosphofructokinase (HPFK-L), and the mouse liver phosphofructokinase (MPFK-L) genes. Characterization of the structure of the HPFK-M gene and its transcript in Epstein-Barr virus transformed B-cell lines derived from patients with glycogen storage disease type VII (GSDVII or Tarui's disease) demonstrated that this single-copy gene encodes a normal sized 3.0-kb transcript in the four cases examined. This suggests the lesion in these cases represents either a point mutation or possibly a small insertion or deletion resulting in the synthesis of a defective HPFK-M protein. Analysis of the 5'-flanking region demonstrated the presence of a functional promoter located within 114 nucleotides of a proposed transcription initiation site. This promoter was active in the human cervical carcinoma cell line, HeLa S3, the dedifferentiated human hepatoma cell line, HepG2.1, and the mouse myoblast cell line, C2C12, suggesting this promoter has a broad cell-type specificity. In addition, from the known HPFK-M cDNA sequences, this observation indicates that the HPFK-M gene has a second promoter located upstream from the genomic region isolated in this study.
Introducción: Los tiempos de atención médica son un factor relevante para la mortalidad por infarto agudo de miocardio con elevación del segmento ST (IAMCEST).Objetivos: Evaluar los tiempos de ...reperfusión en pacientes con IAMCEST participantes de un programa de atención médica cardiológica basada en telemedicina en la provincia de La Pampa durante el período transcurrido entre agosto de 2018 y diciembre de 2021.Material y Métodos: Este programa consiste en la protocolización de la atención de los pacientes que cursan un síndrome coronario agudo (SCA) en las diferentes localidades de la provincia, con asistencia cardiológica remota las 24 horas del día, que incluye tanto la asistencia diagnóstica como la coordinación de las medidas terapéuticas, incluyendo la posibilidad de administrar trombolíticos a nivel local, con asistencia remota.Resultados: De un total de 72 IAMCEST evaluados, 44 recibieron como terapia de reperfusión trombolisis, 25 angioplastia primaria, y 3 trombolisis seguida de angioplastia de rescate. De los 47 sujetos que recibieron trombolisis, sólo 5 requirieron de traslado al centro de referencia para realizar este procedimiento. La mediana de tiempo puerta-aguja fue de 24 minutos y el tiempo puerta-balón fue de 105 minutos. El 28% de los sujetos con angioplastia primaria tuvieron un tiempo puerta-balón inferior a los 90 minutos y el 53,2% de los tratados con trombolíticos cumplieron con un tiempo puerta-aguja menor a 30 minutos. Conclusiones: La implementación de un programa de atención descentralizada guiada por telemedicina se asoció a un elevado porcentaje de cumplimento de las metas de implementación de la terapia de reperfusión basada en fibrinolíticos.
Neurons undergo substantial morphological and functional changes during development to form precise synaptic connections and acquire specific physiological properties. What are the underlying ...transcriptomic bases? Here, we obtained the single-cell transcriptomes of
olfactory projection neurons (PNs) at four developmental stages. We decoded the identity of 21 transcriptomic clusters corresponding to 20 PN types and developed methods to match transcriptomic clusters representing the same PN type across development. We discovered that PN transcriptomes reflect unique biological processes unfolding at each stage-neurite growth and pruning during metamorphosis at an early pupal stage; peaked transcriptomic diversity during olfactory circuit assembly at mid-pupal stages; and neuronal signaling in adults. At early developmental stages, PN types with adjacent birth order share similar transcriptomes. Together, our work reveals principles of cellular diversity during brain development and provides a resource for future studies of neural development in PNs and other neuronal types.
Transcription factors specify the fate and connectivity of developing neurons. We investigate how a lineage-specific transcription factor, Acj6, controls the precise dendrite targeting of Drosophila ...olfactory projection neurons (PNs) by regulating the expression of cell-surface proteins. Quantitative cell-surface proteomic profiling of wild-type and acj6 mutant PNs in intact developing brains, and a proteome-informed genetic screen identified PN surface proteins that execute Acj6-regulated wiring decisions. These include canonical cell adhesion molecules and proteins previously not associated with wiring, such as Piezo, whose mechanosensitive ion channel activity is dispensable for its function in PN dendrite targeting. Comprehensive genetic analyses revealed that Acj6 employs unique sets of cell-surface proteins in different PN types for dendrite targeting. Combined expression of Acj6 wiring executors rescued acj6 mutant phenotypes with higher efficacy and breadth than expression of individual executors. Thus, Acj6 controls wiring specificity of different neuron types by specifying distinct combinatorial expression of cell-surface executors.
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